Announcement

Collapse
No announcement yet.

Idle question; Do I need a new voltage regulator?

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    Idle question; Do I need a new voltage regulator?

    Well, I *think* I need a new voltage regulator.
    I've got a european spec 1986 320i (which means it has a 6 cylinder M20 and L-Jetronic.)

    It idles at 8-900 rpm until I put an electrical load on it like the headlights. Then the idle will vary regularly and consistently from 500 to 1000, with a period of about 2 or 3 seconds. My cheap LCD display voltmeter shows a voltage variation of about 13 to 14 volts. I bet if I had an analog or true RMS voltmeter it would show a much larger variation.

    But which comes first? Does the power drain cause the surging idle or does a poor state of tune cause inability to adapt to the drag from the alternator?
    Anybody seen this before? Is there something more arcane I'm missing?

    As a side issue; where in North America and preferably Canda, do I buy ignition wires of the european internal port (saw-tooth?) style?
    Parts in general for a genuinely eurospec car?
    Tags: None
    #2
    The load, in conjunction with an engine management problem, is what causes the variation in system voltage. Not the other way around in almost all cases. The first action should be to have a smoke test run to check for intake leaks.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment

      #3
      Rats. I was afraid somebody would say that. A new voltage regulator would be so easy.

      So the next steps are,I think,
      1/ Check for intake leaks (again)
      2/ Try to find ignition wires that fit.
      3/ CO sniffer for idle mixture.*

      *Smoke test! (I know what you mean, but:) ) It runs so rich when cold that last evening I made the Subaru behind me dissapear in a cloud of flammable vapour when I accelerated out of his way.
      Not really a smoke test, sort of a smoke verification...
      And it was so pretty in the setting sun.

      Comment

        #4
        800-900 rpm is too high for idle. you might want to verify your TPS as well.
        AWD > RWD

        Comment

          #5
          TPS was good last time I checked, but I'll check it again.

          The manual I have* says that idle speed is controlled by the L-Jetronic ECU. It gives a spec of 650 to 900 rpm idle for other L-Jet cars listed with adjustable idle.

          *How to Tune and Modify Bosch Fuel Injection, Ben Watson

          Comment

          Previous template Next
          Working...
          X